TCA Cycle: Aconitase

Question 1

True or false: The reaction catalyzed by aconitase is reversible.

Answer 1

True

Question 2

What is the term for a molecule in which removal or modification of one group would make the central carbon atom chiral?

Answer 2

prochiral

Question 3

With what kind of reaction does the aconitase step of the TCA Cycle begin?

Answer 3

A dehydration (water is removed from citrate’s lower arm).

Question 4

True or false: Citrate is a chiral molecule.

Answer 4

False; it is prochiral

Question 5

What type of complex is common in redux processes and is used by aconitase to coordinate the OH group of citrate and facilitate its elimination?

Answer 5

Iron-sulpher complex ([4Fe-4S])

Question 6

What is the intermediate in the aconitase step of the TCA Cycle?

Answer 6

cis-Aconitate

Question 7

What is the second reaction in the aconitase step of the TCA Cycle?

Answer 7

Rehydration of the double bond of cis-aconitate to isocitrate.

Question 8

How many stereoisomers does the rehydration of the double-bond of cis-aconitate produce?

Answer 8

1 (because of aconitase)

Question 9

What is the product of the aconitase step of the TCA Cycle?

Answer 9

Isocitrate